蛋清蛋白源血管紧张素转化酶抑制肽研究进展

在分析蛋清蛋白的组成及酶解性质的基础上,综述了国外蛋清血管紧张素转化酶抑制肽来源、制备方法、降压活性、酶解动力学、结构修饰和包埋技术的研究现状,并对其在食品、医药领域研究和应用的方向进行了展望。以期为我国蛋清蛋白降压肽的研究与开发提供参考。     

酶解蛋清蛋白制备ACE抑制肽的工艺研究

为获取酶解蛋清蛋白制备血管紧张素转化酶(ACE)抑制肽的工艺参数,研究4种蛋白酶酶解蛋清蛋白所得产物对ACE的抑制活性,筛选出胰蛋白酶作为制备蛋清蛋白ACE抑制肽的适宜用酶。运用响应曲面法研究酶解时间、底物浓度([S])和酶与底物质量比([E]/[S])对制备ACE抑制肽工艺的影响,建立以上3因素与ACE抑制率关系的数学模型。结果确定胰蛋白酶酶解蛋清蛋白制备ACE抑制肽的适宜酶解条件为酶解时间4.87h、[S]3.06%、[E]/[S]2.91%、酶解温度45℃、pH7.4,此条件下制备的蛋清蛋白酶解产物ACE抑制率达到50.73%。     

Optimization and Scale‐Up Preparation of Egg White Hydrolysate with Angiotensin I Converting Enzyme Inhibitory Activity

Angiotensin I converting enzyme (ACE) plays an important role in regulation of blood pressure as it converts angiotensin I into angiotensin II (a potent vasoconstrictor). Food protein‐derived ACE inhibitory peptides have been considered as a safer alternative to antihypertensive drugs. In our previous study, three ACE inhibitory peptides were characterized from egg white ovotransferrin and their antihypertensive activity has been validated in spontaneously hypertensive rats. However, it is too costly to prepare these peptides from purified egg white ovotransferrin. The aims of the study were to determine the feasibility of preparing these peptides using egg white and then to optimize the conditions of preparing egg white hydrolysate. Taguchi's method was used to design experiments for optimization, which was established as follows: substrate %, pH of thermoase, time of thermoase digestion, ratio of pepsin to substrate, pH of pepsin, temperature of pepsin, and time of pepsin digestion were 7.5%, pH 8, 90 min, 1%, pH 2.5, 55 °C, and 180 min, respectively. The ACE inhibitory activity (IC₅₀ value) and peptide yield obtained under optimal condition were 30 ± 2 μg/mL and 77.5% ± 0.3%, respectively, which were comparable to the predicted values. Hydrolysate prepared at 150 L reactor showed comparable activity but low peptide yield. Results of this study demonstrated the feasibility of using egg white protein as the starting material to prepare a functional ingredient with potent ACE inhibitory activity.